Ultraviolet radiation is not visible to the human eye but can lead to unwanted optical effects in photography: On the one hand, the UV component in the natural scattered light, which is also known as Raleigh radiation, provides for a strong blue colour, whose full extent is often noticeable only in retrospect. On the other hand the chromatic aberration of high UV lighting components leads to blurriness in the picture. Nowadays, special UV blocking filters 82mm are also gladly used in order to prevent these impairments effectively.\n\nProtection from UV light and damage\nHowever, UV filters - and especially the very durable Rollei Extremium round UV filters - have yet another task: Since they affect the transmitted light only minimally and barely darken it, they simply remain as an additional protective mechanism on the lens. High-quality, valuable lenses usually have to be repaired, which is time-consuming and expensive, if the front element was damaged. Rollei Extremium filters are made of extremely resistant Gorilla® glass and an almost indestructible titanium filter ring. An extensive bath in a special hot liquid ensures that there is an effective exchange of ions on the molecular level in Gorilla® glass and a greatly increased surface tension, which defies sharp edged and pointed objects and prevents further splintering of materialeven in the event of deeper scratches. And even if this barrier falls due to undue force, the filter can simply be unscrewed and the lens remains intact.\n\nUncompromising quality that is checked unrelentingly\nThe additional Luminance Coating puts yet another layer between the filter glass and the most aggressive dirt particles. Oil, water and persistent mud are simply repelled and uncompromising colour neutrality and insensitivity to distortions and reflections are lastingly guaranteed. Without this extreme colour fidelity the picture already loses important information, when it is created and optical authenticity is irreparably lost. All Rollei Extremium round filters in the nine available lens diameters are subjected to ongoing quality tests so that this impressive combination of characteristics works together perfectly. The quality management system developed specially by Rollei outshines the usual approaches of the industry and provides for a unique level of quality. You have the certainty of possessing a truly superior product that survives even the worst treatment and challenging photography projects unscathed.